A fly's eye uses multiple lenses to efficiently collect light originating from a wide angular range. FIG. 1 shows a cross-section of a fly's eye 100 that includes an array of lenses 110 covering a curved surface 120. Each lens 110 has an optical axis along a different direction, and each lens 110 forms an image of a different portion of a surrounding scene on a corresponding image plane 130. Fly's eye 100 can locate an object by identifying which of the lenses 110 form images of the object and can track the object as the object moves from the field of one lens 110 to the next.
Astronomical detectors such as cosmic ray detectors have mimicked the properties of a fly's eye using arrays of separate sensors. In such systems, each sensor has a sensing axis pointed in a different direction to enable simultaneous detection of radiation from all directions of sky. These detector systems are generally large, complex, and expensive.
Manufacturing an inexpensive fly's eye detector using integrated circuit technology would be very desirable for applications requiring information from a wide-angle field. However, a solid-state detector having the configuration of fly's eye 100 would be difficult to construct because current semiconductor processing techniques are generally not intended for processing of globally curved surfaces. For example, conventional photolithography generally has a limited depth of focus and may be unable to accurately control patterns on a hemispherical surface. Many other semiconductor manufacturing techniques are similarly ill suited for fabrication of devices such as image sensors or photodiodes on a curved surface.
Methods and structures that provide features of a fly's eye in an inexpensive detector system constructed using conventional semiconductor processing techniques are sought.